Sumitomo Electric Industries, Limited

Kenji Abiru

Naoki Ayai

Toshiaki Okumura

Tetsuo Akita

This conversion device converts DC powers from a plurality of DC power supplies, to AC power and supplies the AC power to a load. The conversion device includes: a filter circuit including an AC reactor and a first capacitor; a DC/AC inverter connected to the load via the filter circuit; DC/DC converters provided between the respective plurality of DC power supplies and the DC/AC inverter; a second capacitor provided between the DC/AC inverter and the DC/DC converters; and a control unit configured to set a current target value for each of the DC/DC converters to thereby be synchronized with current of the AC power, based on voltage of the AC power, voltage variation due to current flowing through the AC reactor and an impedance thereof, reactive currents respectively flowing through the first capacitor and the second capacitor, and voltage of each DC power.

Conversion device

An inverter device includes a circuit configuration for converting, to AC power, DC powers respectively given from a first power supply and a second power supply which outputs power with voltage lower than that of the first power supply. The inverter device includes: a first step-up circuit; a second step-up circuit; an inverter circuit connected to both step-up circuits connected in parallel to each other, the inverter circuit configured to convert powers given from both step-up circuits to AC power; and a control unit configured to multiply a power value including the AC power outputted from the inverter circuit, by a ratio of a power value of the DC power of each step-up circuit to a total power value obtained by summing the DC powers of both step-up circuits, and set a current target value for each step-up circuit based on a value obtained by the multiplication.

Inverter device

Provided is a conversion device that converts DC power provided from a DC power supply, to AC power and supplies the AC power to a load, the conversion device including: a filter circuit connected to the load and including an AC reactor and a first capacitor; a DC/AC inverter connected to the load via the filter circuit; a DC/DC converter provided between the DC power supply and the DC/AC inverter; a second capacitor provided between the DC/AC inverter and the DC/DC converter; and a control unit configured to set a current target value for the DC/DC converter to thereby be synchronized with current of the AC power, based on voltage of the AC power, voltage variation due to current flowing through the AC reactor and an impedance thereof, reactive currents respectively flowing through the first capacitor and the second capacitor, and voltage of the DC power.

High-frequency switching type conversion device

An inverter device includes: a step-up circuit; an inverter circuit; a control unit for controlling the step-up circuit and the inverter circuit; and a reactor provided on an electric path for outputting the converted AC power to an AC system. An output current target value is calculated based on an input power value of DC power and a voltage value of the AC system, and a current target value and a voltage target value for the inverter circuit are calculated based on the output current target value, to control the inverter circuit. A current target value for the step-up circuit is calculated based on a current target value and a voltage target value that are common with the inverter circuit, and on a DC input voltage value, to control the step-up circuit. Thereby, output of the AC power is controlled.

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Osaka, Japan

Kenji Abiru